Table A-6 lists critical values for r for selected values of n and . More generally, critical r values

can be found by using the formula

= 2 + 2

where the t value is found from the table of critical t values (Table A-3) assuming a two-tailed case with df = n - 2. Use the formula for r given here and in table A-3 (with df = n - 2) to find the critical r values corresponding to

1: 0, = 0.02, 27.